Power control



Sept. 3, 1946. G. M. HOL-LEY, J

POWER CONTROL Filed March :5, A1944 INVENT 0R.

4120249@ Molley c:

Patented Sept. 3, 1946 VPOWER CONTROL George M. Holley, Jr., Grosse Pointe, Mich., as-

-signor to :George M. Holley and Earl `'Holley ApplicationMarch '3, 1944, Serial No. 524,977

i 9 Claims.

1 The object of this invention is to regulate the throttle of a supercharged airplane engine Ain which the throttle is located inthe air entrance leading to the supercharger.

The specic object is Ato regulate "thesupercharger pressure 'so that when lthe supercharger pressure exceeds thepressure ofthe atmosphere by a certain number of pounds per square inch, the air inlet throttle is closed so vas to prevent the supercharger pressure from exceeding the number of pounds per square inch above the atmosphericpressure selected bythe pilot.

The regulation of an engine by automatically controlling the number `of pounds per square inch increase of the pressure ofthe ysupercharger and also the manual selection of the amount of this increase is old. One example of this is the AFrench Patent No. 398,637 to Bihan et al., dated March 29, 1909. The defect of Bihan was that `when the plane ascended into'the air, there was a loss of power due to -the fall in the density fof the air. Hence, itis necessary, `if Ysuch a "loss'is to be avoided, to obtain `an increasing -difference between lthe atmospheric pressureand the pressure generated by the supercharger `with .altitude. This lpressure is `commonlt7 known `as gauge pressure. 1f the attempt-ismade to give a constant absolute pressure on the engine side of the supercharger, then because ofthe decrease in the exhaust backpressure the netresult is that there is Van increase of power with altitude at the rate of 1.2% per 1,000 feet, approximately. The greatest power, however, is needed when getting koff the ground at sea `level and, therefore, this is the opposite of what is "desired,

I, therefore, propose to vary this increase in manifold air pressure with altitude `so as to 'give the maximum supercharger pressure when taking off at sea level.

The figure shows the preferred form of Vention.

In the figure, Ivis the `pilotfs hand control. '2 is a link connecting it with a lever 3 which -is connected through suitable Voperating means -including the mechanismV enclosed in casing AA `to a rod 4 which is connected to a :throttle Barometric element 6, connected through vsuitable operating `means including the device B- to a c am 'I,V controls the fulcru-m 8 so that the position of the fulcrum 8 varies with altitude. Manual control modilied by altitude is thus available. The roller 8 is mounted on a connecting rod 35 which slides in the stationary .element 3.1 and which connects the roller 4llw-ith .a pin 36. Pin 36 is the fulcrum for the lever 3.

my in- A and B are two :servo motors of well known types. The lever 3 z,engages witha button 9 which inits turn .engages with a compression spring I0 which engages with a ange of the rod I4. `Rod I4 is connected to the diaphragm .II which forms the right hand wall `of a chamber `I2 which is connected through .pipe I8 withan inlet manifold I9 on the engineside of a supercharger 20 which is connected to the air entrance `2| in which is located the throttle 5. The rod I4 is so .constructed and arranged as .to act as v.aservo motor valve for operating Athe piston ,I3 which, when the rod I4 moves vto .the left, also moves to the left, compressing the compression spring .2.2.

Oil pressure is admitted through pipe IT .and escapes through passage 23. When .the rod I4 is moved to the left, the ports ,in the rod I4 deliver the oil pressure into the chamber 24.0!'1 the right hand side of .thepiston I3 and the throttle 5 continues toropen `until ,the supercharger `pressure in the inlet mani-fold `I9 vand in chamber I2 increases .until the diaphragm .I.I moves to the right restoring the valve rod I4 to its neutral position. XOilis allowed Lto .escape `from the left hand sideof piston I3, `that is, from chamber 25 through passage ,2.6. past port in rod IA to the oil outlet 23 when the valve rod .IA iS `left 0f .the neutral position shown.

Before the engine begins fto operate, there is no oil pressure ,and elements I5 vand I6 are provided. Elements I5 and I6 are .spring loaded and move .dOWll ,and engage with the rod 14. The rod I4 is connected directly to the piston I3 so that when this happens there is a `rigid connection from rod I4 to the rod 4 ,so that 'the throttle 5 can be manually `opened to start the engine.

When the Loil pressure s .,admtted, the elements I5 and I6 are pressed upward, compressing the spring contained inside ,elements I5 and 16. When this happens, the `rod 'I 4 is ,free and, therefore, the piston I3 responds to the oil pressure, or `rather the .dinerence .between the oil .pressure in pipe ,II andthe .Oil pressure in rpipe 23. The result is that the piston responds to the .mote- `ment of rod I4 whereas the rod I4 `vcould exert only a relativelysmall .pressure on piston I3,.but

a large pressure is now 4exertedand so the .throttle 5 opens until the pressure iin `the pipe IB 'is large .enough to generate .sllllicient snpercharger `pressure in `chamber .I2 -toloppose the ,compression .of

the spring I0 when the diaphragm II and the rod I4 move into their neutral positions and the throttle v5 =.ceases -to open. -The liquid -.entering at I.'I Alowfs through a port 4.3, which engages withA efgrvveMI-inzthe rod M, ,Whenfrod |4 is moved n 3 to the left, the oil under pressure is thus admitted to chamber 24 from the port 44 through ports 45, 46 and 41.

When the rod I4 is moved to the right, oil under pressure in groove 44 flows into chamber 25 along ports 48, 49 and 26. Meanwhile, the liquid from the opposite side of piston I3 escapes to the outlet 23 as follows: when piston I3 is moved to the left by oil pressure in 24 as a result of moving rod I4 to the left, then port 48 is put in communication with a groove 52 in rod I4, which is in communication with a port 53, which is connected with the outlet port 23.

When piston I3 is moved to the right by oilV pressure in 25 as a result of moving rod I4 to the right, a groove 50 in rod I4 is put in communication with the port 45 and so through the port 5I with the outlet port 23.

The casings A and B, as well as the housing 54 containing the chamber I2, are all stationary.

Altitude control The roller 8, which acts as the pivot for lever 3, is held in engagement with the cam 1 by the spring 21. The expansion of the barometric element 6 moves valve rod 28 to the right which permits oil pressure to escape from the right hand side of piston 29 to pipe 3|. Oil pressure is then admitted through a pipe 30 to the left hand side of piston 29. IThe piston 29 then rotates the cam 1 clockwise. The piston 29 is pushed to the left by the compression spring 39 and pushes the yoke 38 to the right and thus pushes the rod 49, which engages with a slot 42 in the lever1, which has a fulcrum 4I in the stationary .element 31. A groove 55 in piston 29 is in communication with the low pressure pipe 3|. When valve 28 moves to the left, the pressure in chamber 55 to the left of piston 29 falls to the pressure in pipe 3l due to the restriction 51. yj58 is a corresponding restriction between the high pressure line- 39 and the chamber 59 to the right of thepiston 29.

When starting the engine, before oil pressure becomes available, the spring loaded element 32 locks the cam 1 in place so that until oil pressure is obtainable, the fulcrum 8 is held in a fixed position. Oil pressure admitted from pipe 30 unseats the locking device 32.

Operation Whenever the throttle valve 5is in equilibrium, that is to say, when the pressure in the inlet manifold I9 is high enough to balance the compression of the spring I determined by the position of the manual control lever I and the altitude cam 1, the diaphragm II is in the position shown in the drawing. Hence, the spring I0 is compressed against the flange of the rod I4 which assumes a fixed position whenever the throttle is in equilibrium. Hence, the position of the lever 3 determines the position of the throttle 5 and the position of the lever 3 is determined jointly by the position of the manual control lever I and the position of the altitude cam 1 which automatically increases the Vgauge pressure with altitude. More specifically, the position of the lever 3 determines the differential pressure between the manifold air pressure and the atmospheric pressure and this pressure differential is modified by the lever I manually and by the barometric capsule 6 automatically through` the cam 1.

What I claim is:

V1. A throttle control for a supercharged aircraft engine comprising anair entrance to said engine, a throttle valve therein, a lever therefor,

a chamber, a moving Wall associated therewith, a passage connecting said chamber with the engine side of said supercharger, spring loading means engaging with said moving wall in opposition to the supercharger pressure, the pressure on the other side of said wall being atmospheric, manually controlled means for controlling said spring loading means, barometric responsive means for modifying said spring load on said moving wall at all positions of said manual means, a connection from said moving wall to said throttle lever whereby the position of the throttle is controlled by the movement of said moving wall in response to changes in the pressure of the supercharger and this supercharger pressure is balanced by said spring loading means which is regulated jointly by the manual control means and by said barometric means.

Z. A device as set forth in claim l in which a servo motor is interposed between said movable wall and said throttle.

3. A device as set forth in claim 1 in which a servo motor is interposed between said barometric means and said spring loading means.

4. A device as set forth in claim l in which a servo motor is incorporated in said connection from said moving wall to said throttle a'nd in which a servo motor is incorporated between said barometric responsive means and said spring loading means.

5. A throttle control for a supercharged aircraft engine comprising an air entrance to said engine, a throttle valve therein, a lever therefor, an air chamber, a moving wall associated with said chamber, operative means connecting said wall with said throttle lever, a passage connecting said chamber with the engine side of said supercharger, spring means engaging with said wall, the pressure on the other side of said wall being atmospheric, a control lever engaged with said spring means, manually controlled means for moving said lever, barometric responsive means for varying the fulcrum of said control lever whereby the spring load on said movable wall is regulated jointly by the manual control means and by said barometric control means and the throttle lever is opened and closed until the supercharger pressure balances said spring load.

6. A throttle control for a supercharged aircraft engine comprising an air entrance, a throttle valve therein, a lever therefor, a servo motor having a piston connected to said lever so constructed and arranged as to open and close said throttle, an air chamber, a moving wall associated therewith, a passage connecting the air chamber with the engine side of said supercharger, a valve controlling said servo motor, said valve being connected to said moving wall, spring loading means associated with said moving wall, the pressure on the other side of said wall being atmospheric, a control lever engaging with said spring loading means, a barometric responsive device, a servo motor associated therewith and connected to the fulcrum of said control lever, manual means for moving said lever whereby the spring loading means is controlled both manually and automatically.

7. A device as set forth in claim 6 in which the servo motors are so constructed and arranged that in the absence of oil pressure to operate said servo motors, the rst servo motor is operated mechanically by said moving wall and the moving wall is positively moved by said control lever and the second servo motor is inoperative to move said fulcrum. I l.

8. Throttle control for supercharged aircraft .engines comprising, yielding means, throttle control means responsive to said yielding means and to the amount of supercharger pressurerelative to the atmospheric pressure, said supercharger pressure being arranged so as to act in opposition to said yielding means, an induction throttle valve for said engine connected to said throttle control means, so that an increase in supercharger pressure closes the throttle valve, means responsive to changes in the atmospheric pressure, so constructed and arranged as to vary the said yielding means directly, and thus indirectly the supercharger pressure opposed thereto, so as to vary the position of said throttle Valve with altitude, manual means so constructed and arranged as to cooperate With said atmospheric pressure responsive means in the control of said yielding means directly and thus indirectly ci said supercharger pressure so that at any given altitude the throttle is closed by said supercharger pressure as said pressure rises above that of said yielding means selected by said manual `control means to oppose said supercharger pressure.

9. Yieldable throttle control means for super charged aircraft engines comprising, a manually operated lever, yielding means associated therewith, throttle control means responsive to the said yielding means and to the amount of supercharger pressure relative to the atmospheric pressure, said yielding means being adapted to oppose said supercharger pressure, an induction throttle valve for said engine connected to said control means, so that an increase in the yielding means opens the throttle, and an increase in the supercharger pressure closes the throttle, means responsive to changes in the atmospheric pressure, so constructed and arranged as to vary said yielding means and the said supercharger pressure, so as to vary the position of said `throttle valve With altitude at every position of said manual control means, manual control means so constructed and arranged as to cooperate 'with said atmospheric pressure responsive means in the control of said yielding means and of said supercharger pressure.

' GEORGE M. HOLLEY, JR. 

